Our modern day business environment is replete with examples of business transactions which illustrate the need for being able to distinguish valid signatures from those which have been forged. It was early learned through sad experience that even a careful study of an individual's signature by a merchant or banker is not an adequate safeguard since a skilled forger can often fool anyone who is not an expert. The problem of discerning between a forged signature and a valid signature is a problem which many have attempted to solve in the prior art.
Many of the more modern attempts have sought to solve the problems by using distinct characteristics of an individual's signature which can be detected and converted into electrical signals which can be processed and compared with a representation of an authentic signature for determination as to whether or not the signature currently being investigated is authentic or is a forgery.
One of the characteristics of an individual's signature, which has been the focus of considerable attention, is that of the characteristic pressure applied by the signer during the signing of his signature. While this type of characteristic is not discernable to one who studies the signature on a piece of paper or some document, it can be detected and studied by other means. It has been found that the pressure variations inherent in an individual's act of handwriting his signature are characteristic of that individual's signature and can be used with an acceptable degree of accuracy for verification purposes.